Jack



Patented Dec. 6, 1932 JOHN A. spam, or onnnen, MASSACHUSETTS moi:

Application filed November 24, 193.0,,Seria1 No. 497,718.

This invention relates to a jack for use in lifting automobiles and forother lifting purposes.

The principal objects of the invention are to provide a jack having fewparts, easily made of pressed sheet metal; to provide a jack which'willbe comparatively inexpensive to manufacture and to assemble; to protectthe parts inside from dirt and to make a jack which cannot be tamperedwith.

Other objects and advantages of vtheinvention will appear hereinafter.

Reference is to be had to the accompanying drawings, in which Fig. l isa side view of a jack constructed in accordance wi h this invention andshown in its contracted position; i

Fig. 2 is a similar view of the jack in expanded position, parts beingbroken away to show interior construction;

Fig. 3 is a plan of the jack;

Fig. 4 is a central vertical sectional view showing the interior of thejack;

Figs. 5, 6 and 7 are sectional views on horizontal lines 5-5, 6-6 and 77respectively, and i Fig. 8 is a plan of the operating gear.

This jack is constructed almost entirely of pressed metal. A pressedmetal base 10 is constructed with its ends at '11 raised at an angle sothat the jack can be drawn over the ground readily and it has verticalsides 12 to strengthen it. To it is secured a cylindrical pressed metalcasing 13. This casing is provided with integral projections 14 at adistance from the top pressed out of the material of the metal,preferably. The projections are horizontal on top and spaced apart.

On this partition rests a bevel gear 15 meshing with a pinion 16 locatedin a cylindrical casing 17 welded into the wall of the casing 13. Thispinion is provided with a square opening 18 for a wrench or handle foroperating the device. Obviously the rotation of the handle will rotatethe gear 15, at a somewhat lower rate of speed.

This gear 15 is provided with a square opening 19 through it, preferablywith rounded corners, and in this opening operates a vertical liftingelement '20, which is formed of sheet metal, as shown particularly inFig. 6, formed into a substantiallysquare shape with the cornersrounded. off. A

screw-thread is formed on these corners which screw-thread obviously isnot continuous but consists of four parts equally spaced around. it. Onthe inside the lifting element is made with a square passagetherethrough.

On the top of the casing 13 is a ca 22,

flat on topand secured to the top of the cas- 69 the threads in the nut23 and this element will be positively raised or lowered by itsrotation.

On the inside the element 20 is also provided with a screw-thread 24between the square corners. This also is a discontinuous thread. The nut25 fits this thread and is provided with a hexagonal post 26 integralwith it and projecting through a plate 27 freely resting on the top ofthe element :20 and having a hexagonal hole therethrough fitting thepost 26,. On the post is a work rest 28 of ordinary construction but, asshown, having grooved crossways' so that there will be less opportunityfor it to turn 0n the work. The plate 27 projects outwardly from themember 20 and it has a pair of 5 vertical guides 29 extending down fromit through a pair of openings in the cap 22 and also between theprojections 14. These guides constitute nieansfor preventing this plateand the post 26 from turning even when there is no load on the jack.

,In operation, the turning of the handle turns the gear 15 whichturnsthe liftingmember 20. By reasonof its screw-threads this membermoves vertically in the extension or nut 23- Meantime the post 26 Whichis held from turning by the plate 27 is moved vertically by thefactthatthis screw-thread 25 meshes with the internal screw-thread 24;.

It will be seen that the two screw-threads 0 are right-handed andleft-handed respectively. Therefore the two members 20 and 26 will risetogether and fall together. The plate 27 rests freely on the top of thelifting member 20 and consequently moves up and down with it, beingmoved down by gravity alone.

As the lifting member 20 is made of pressed metal turned up into asquare tube with a.

seam on one side, which preferablyis welded,

and as the screw-threads are easily cut on it,

there is very little machining and the parts are all made of sheetmetal. In fact the gears also can be made of sheet metal butmaking hesetwo gears this invention. The head 28 will rise twice as fastapproximately as would be the case if only one screw-thread ofcorresponding pitch were employed. The jack is stable and the interiorparts are protected from dirt and moisture by the plates 22 and 27,especially when the jack is in its contracted position and not in use.The plate 27 with its guides 29 prevents the user from rotating the post26 and thus changing the relationship between the parts 20 and 2'5.These are originally' tirely contracted the plate 2? will rest on thecap 22 and the bottom of the head 28 substantially on the plate 27. Asthe user can not change this relationship, it will always come back tothis position and the jack is always in condition to extend to itsfullest extent. I

Although I have illustrated and described one form of the invention I amaware of the fact that modifications can be made therein by any personskilled in the art without departing from the scope of the invention asexpressed in the claims. Therefore I do not wish to be limited in thisrespect but what I do claim is '1. In a jack, the combination with acasing having a horizontal wall therein, a gear resting on said wall,said casing having a cap fixed thereto and provided with an integral nutextending downwardly therefrom and screw-threaded inside, a verticallifting member formed of a sheet of pressed metal in a non-circularshape with a screw-thread thereon meshing with the threads in said nut,the gear having an opening therethrough of the same shape as saidlifting member whereby the lifting member will rotate with the gear,said lifting member having a thread on the interior thereof, a,non-circular post within said lifting member having a screw-thread onthe bottom fitting the screw-thread in the interior of the liftingmember, means carriedup and down with the lifting member guided by thecap and fitting the post, to prevent it from turning, and means forrotating the gear.

-2. In a ing having a aek, the combination with a cashorizontal restinside, and a cap does not constitute a part of arranged so that whenthe jack is enbeing threaded and fitting the threads on the post, saidpost being hexagonal above its screw-threads, and a guide plate on thetop of the lifting member having an opening fitting said post to preventit from turning and being provided with legs extending downwardly, thecap having openings therethrough for receiving said legs and guidingthem to move vertically.

3. In a jack, the combination with a casing having a horizontalpartition inside integral with the casing and located above the centerthereof, and a cap on the top of said casing fixed thereto and having anintegral down- I wardly extending internal nut, of a gear on saidpartition, a lifting member having a noncircular shape passing 7 throughthe gear which has an opening the same shape and size, the liftingmember having a left-hand T ed screw-thread outside around its cornersto fit the screw-threads of the internal nut, a post within the liftingmember having a right-hand thread on its bottom, the lifting memberbeing threaded throughout its length and fitting the threads on thepost, said post being non-circular above the screwthread, a guide plateresting on the top of the lifting member and having an opening fittingsaid post to prevent it from turning and be-' ing provided with legsextending downwardly, the cap on the casing having openings therethroughfor receiving said legs and guld ing them to move vertically, and meansfor turning said gear.

In testimony whereof I have hereunto af-

